<p>The empirical Moore?s law essentially states that the ability of large-scale integration (LSI) becomes twice denser every 18 months. This law has held true, even at the beginning of the 21st century. If the law still holds in the coming decade, we will see a micro-processor with one billion transistors sometime around 2005, and a CPU with 10 billion transistors sometime in the 2010s. Scientists say that the human brain has about 1.4 billion neurons. But we must throw away the simple view that one neuron could correspond to one tran-sistor. Our brains and the current digital computer work in very different manners. So comparing the numbers of neurons and transistors is just a matter of general interest with no real application. Still, it is impressive that designers can pack so many logic devices in a single LSI.</p>